Technical and Design Characteristics of Trammel Nets Used in Lake Manzalah, Egypt
El-Azab
El-Bokhty
Fisheries Dept., NIOF, Egypt
author
text
article
2017
eng
The present research was carried out during Autumn 2016 with the aim of studying the technical and design characteristics of the widely used trammel nets in Lake Manzalah, as an attempt to be one of a data base that describe the different fishing gears used in Egypt. A number of net units were randomly used as samples. Results showed that such nets are used in collaboration with small fishing wooden boats (canoes) reinforced with a layer of fiber glass of the third class with an average number of 2 men. The dimensions of trammel net unit ranged between 20 and 25 meter long and a height of 0.5 to 1 meter. Trammel nets are formed of three netting panels, the stretched mesh size of the middle layer averaged # 40.82 mm while that of the outer layer was 125.24 mm. The upper and lower ropes were locally made of 3- strand staple fibers. Small sized cork floats were mounted on the upper rope (av. # 3 / 1 m) and lead sinkers to the lower rope (av. # 5 – 6 piece / m) of a total weight of 2-3 Kg per net unit. The netting materials were of polyamide monofilament of an average diameter (ɸ) 0.126 mm for the inner layer and ɸ 0.22 mm for the outer one. The horizontal hanging coefficients ranged between 0.60 and 0.70 for the outer layers and between 0.40 and 0.55 for the inner one. The results showed that such nets don't match the criteria for catching moderately sized fish (Average length 15 cm) of tilapia especially the mesh opening of the inner layer for conserving the fishery stocks and sustainable fishery.
Egyptian Journal of Aquatic Biology and Fisheries
The Egyptian Society for the Development of Fisheries and Human Health (ESDFHH)
1110-6131
21
v.
3
no.
2017
1
10
https://ejabf.journals.ekb.eg/article_3535_302db97f97616d613c3d53d9aafc78c9.pdf
dx.doi.org/10.21608/ejabf.2017.3535
Antioxidant Defense System Alternations in Fish as a Bio-Indicator of Environmental Pollution
Magdy
Khalil
Department of Zoology, Faculty of Science, Ain Shams University, Cairo, Egypt
author
Nahed
Gad
National Institute of Oceanography and Fisheries (NIOF), Cairo, Egypt
author
Nasr
Ahmed
National Institute of Oceanography and Fisheries (NIOF), Cairo, Egypt
author
sally
Mostafa
National Institute of Oceanography and Fisheries (NIOF), Cairo, Egypt
author
text
article
2017
eng
The present study carried out to clarify the impact of heavy metals (Fe, Zn, Cu, Mn and Cd) pollution of Rosetta Branch on the antioxidant defence system activities and lipid peroxidation indicator MDA levels in O. niloticus tissues (liver and white muscles) collected from three stations from Rosetta Branch of River Nile in summer2014 and winter 2015. Rosetta Branch of River Nile exposed to high input of agricultural drainage water, sewage and industrial waste water which influence the living organisms especially fish. In the present study results revealed that the concentration of heavy metals (Fe, Zn, Cu, Mn and Cd) in water and fish samples increased in station II and III, especially in winter. In muscles of O. niloticus, the accumulation patterns of heavy metals were in the following order: Fe > Zn > Mn > Cu and Cd. The bioaccumulation factor (BAF) in winter was higher than summer. Antioxidant enzymes (SOD, CAT, GPx, GST and GR) activities and the indicator of lipid peroxidation MDA levels showed a significant increase in liver and white muscles of O. niloticus, in stations II and III, especially in winter. Moreover, the antioxidant enzymes activities and MDA levels were higher in liver than white muscles.
Egyptian Journal of Aquatic Biology and Fisheries
The Egyptian Society for the Development of Fisheries and Human Health (ESDFHH)
1110-6131
21
v.
3
no.
2017
11
28
https://ejabf.journals.ekb.eg/article_3536_6e5ec543038cc4f02745d4d7aa506f8f.pdf
dx.doi.org/10.21608/ejabf.2017.3536
Total and Bio-Available Phosphorus in Sediments and Its Contribution to Lake Nasser Eutrophication, Egypt
Mohsen
Darwish
Nile Research Institute
author
text
article
2017
eng
Phosphorus has negatively influences on the ecosystem and causes eutrophication. To assess the degree of eutrophication it is necessary to know not only the total P content in the sediments, but also its bio-available forms. The main objectives of this study are to assess the distribution of total phosphorus in bed sediment along Lake Nasser, to characterize the phosphorus bioavailable forms in surface sediments, to examine the relationship between phosphorus concentration and other sediment properties and to assess the potential contribution of bioavailable phosphorus in eutrophication. To achieve these objectives, superficial sediment and water samples were collected along Lake Nasser during May 2016. The sediment samples were analyzed for total phosphorus, water soluble phosphorus, plant available phosphorus and grain size distribution. For water, dissolved oxygen, total phosphorus, Chlorophyll-a and transparency are analyzed. The results showed that, the total phosphorus in sediment samples ranged from 550 to 704 mg/kg and showed a temporal variation comparing with the data recorded during May 2009 (P= 0.046). Water soluble-phosphorus (WSP) and plant available phosphorus ranged from 1 to 3.25 mg/kg and 13.8 to 26.9 mg/kg, respectively, which represented 0.15 % - 0.46% and 2.06% - 4.59% of the total sedimentary phosphorus. The total phosphorus, transparency and chlorophyll-a in water ranged from 40 to 60 µg/l, from 1.3 to 2.8 m and from 2.4 to 32 µg/l respectively. The total phosphorus concentration in bottom layer of water column recorded higher values than that in the surface layer and ranged from 55 to 100 µg/l. The results also show that, the depletion of dissolved oxygen concentration near the bottom layer (2.15 mg/l) may enhance the release of P from the sediments. The high positive correlation was found between total phosphorus in sediment and WSP in sediment, clay and TP in water. However, total phosphorus in sediment has strong negative correlation with sand. It’s worth mentioning that, WSP in sediment has a positive correlation with total phosphorus in water, indicated that WSP fraction can release phosphorus easily and increasing the total phosphorus in water. Based on Trophic State Index Calculation (TSI), Lake Nasser ranged from mesotrophic to light eutrophic state. It is recommended that dredging the surface sediments from the sedimentation zone have a positive effect in improving water quality where, dredging removes substantial amount of P stored in sediments.
Egyptian Journal of Aquatic Biology and Fisheries
The Egyptian Society for the Development of Fisheries and Human Health (ESDFHH)
1110-6131
21
v.
3
no.
2017
29
44
https://ejabf.journals.ekb.eg/article_3727_a17cc052275c54aabfcbd9e742284715.pdf
dx.doi.org/10.21608/ejabf.2017.3727
Mangrove Avicennia marina of Yanbu, Saudi Arabia: GC-MS Constituents and Mosquito Repellent Activities
Rafat
Khattaba
Department of Marine Biology, Suez Canal University, Ismailia, Egypt.
author
Tarek
Temraz
Department of Marine Biology, Suez Canal University, Ismailia, Egypt.
author
text
article
2017
eng
A phytochemical analysis of Avicennia marina has been investigated by GC-MS. Avicennia marina leaves, seeds, flowers, stems indicate the presence of, steroids, tannins, glycosides, carbohydrates saponnins, sterols, terpenoids and phenols. The Avicennia marina revealed the presence of active medicinal constituents by GC-MS. This study also helped to identify the formula and structure of biomolecular therapy which can be used as drugs. Avicennia marina was tested for their mosquitocidal activities. The toxicities were examined against the lab. Strain of 3rd instar larvae of Culex pipiens. The results showed that extracts of seeds and leaves of Avicennia marina were more efficient than other parts against third instar larvae of Culex pipiens mosquito. In view of these results, the purified active compounds from the most effective samples found in our studies could be effective in killing mosquito larvae or repelling adult female mosquitoes in an economical and safe manner.
Egyptian Journal of Aquatic Biology and Fisheries
The Egyptian Society for the Development of Fisheries and Human Health (ESDFHH)
1110-6131
21
v.
3
no.
2017
45
54
https://ejabf.journals.ekb.eg/article_4003_c523e66342692277e77137e7ab8bb276.pdf
dx.doi.org/10.21608/ejabf.2017.4003
Zooplankton Community Structure of Lake Edku, Egypt
Montaser
Hassan
Zoology Department, Faculty of Science Ain Shams University
author
Magdy
Khalil
Department of Zoology, Faculty of Science, Ain Shams University
author
Abd El-Halim
Saad
Department of Zoology, Faculty of Science, Ain Shams University
author
Safwat
Shakir
Texas Gulf Coast Environmental Data (Texged) Center, Prairie View A&M University
author
Gamal
El Shabrawy
National Institute of Oceanography and Fisheries, Egypt
author
text
article
2017
eng
This work was designed to determine and assess the faunal zooplankton community structure in Lake Edku, Egypt, to explain the present status of zooplankton and water quality to assess the ecological impacts and the induced change in the zooplankton community. Zooplankton and water samples were collected seasonally. Seven sampling stations were selected to represent different habitats of the Lake that were classified in this study to three distinct habitats; Body of the lake (BL), Drainage (D) and Lake- Sea Connection (LSC). Several physical and chemical variables were studied, such as temperature, transparency, alkalinity, water pH, chlorosity, electrical conductivity, water depth, dissolved oxygen (DO), chemical oxygen demand (COD), biological oxygen demand (BOD), and water hardness. Zooplankton community consisted of 72 species dominated by three groups, Rotifera, Copepoda and Cladocera. These groups were representing 89.5%, 6.8% and 2.3% of total zooplankton density, respectively. The index of species abundance (ISA) and modified index of species abundance (MISA) showed that the small sized animals, such as Rotifera became the most dominant especially, genus Brachionus, which is considered as an indicator for organic pollution and eutrophication. Community ordination, trellis diagram and other biostatistical and multivariate analyses techniques showed that within the lake, similar ecological habitats have similar community structures for zooplankton and differ among different habitats. Comparing the present results with older data of other workers; it was appeared that zooplankton community shifted from dominance of Cladocera and large zooplankton forms to rotifers and small zooplankton by increasing eutrophication. The results of this study provide a useful knowledge about zooplankton community structure and species composition over the long term changes in the studied ecosystem.
Egyptian Journal of Aquatic Biology and Fisheries
The Egyptian Society for the Development of Fisheries and Human Health (ESDFHH)
1110-6131
21
v.
3
no.
2017
55
79
https://ejabf.journals.ekb.eg/article_4129_ea2eccc17a0c77efd2c0f1ae5a566c82.pdf
dx.doi.org/10.21608/ejabf.2017.4129
The Marine Ichthyofauna of Egypt
Elsayed Haroun
Akel
Kait-Bey, Alexandria, Egypt.
author
Paraskevi
Karachle
Hellenic Centre for Marine Research, 46.7 km Athens Sounio ave., P.O. Box 712, 19013 Anavyssos Attiki, Greece.
author
text
article
2017
eng
This work is the result of a compilation of the Egyptian ichthyofauna, aiming to provide a basis for monitoring and assessing potential biodiversity changes in the area. The main sources used were peer-reviewed papers and grey literature (i.e. unpublished reports, theses, conference proceedings, etc), FishBase and the Global Biodiversity Information Facility. Overall, 956 fish species (71 Elasmobranchii, 2 Holocephali and 883 Actinopteri) have been recorded to date from the Egyptian marine waters. Of those, 592 species are present only in the Red Sea, 263 species are present only in the Mediterranean Sea, and the remaining 101 species are reported from both seas. In addition to those 956 fishes, 52 species have been reported based on photos, but these records require further documentation with samples. Finally, for 64 species, which are listed in FishBase as belonging to the ichthyofauna of Egypt, no publication or museum sample report verifying their presence in Egypt could be traced. Thus, their presence remains questionable until further evidence becomes available.
Egyptian Journal of Aquatic Biology and Fisheries
The Egyptian Society for the Development of Fisheries and Human Health (ESDFHH)
1110-6131
21
v.
3
no.
2017
81
116
https://ejabf.journals.ekb.eg/article_4130_585cc440ab800a610925ee5b134d28ec.pdf
dx.doi.org/10.21608/ejabf.2017.4130